SCH 



557 



SCH 



SthlUMtl- 



burg 



li 

 Srh\vut/. 



em 



that article. See Macdonald Kinneir's Memoir of the 

 I't-rxitin I-'. in jiirt: 



SCH LI SSKLBURG, a town of Russia, situated on 

 the left bank of the Neva, at its outlet from Lake 

 Ladoga. It is defended by a fort about 1 Hi yards 

 square, built on an island in the Neva about 350 yards 

 long. The walls, built of stone and brick, are about 

 50 feet high and very thick. Cotton and porcelain are 

 manufactured In re. Population about 3 L 200. 



SCHNEEBEltG, a town of Saxony situated on an 



inence near the Alulda. It contains several public 

 schools. Smalts are manufactured here on a large scale. 

 The chief products of the mines in the vicinity are iron, 

 cobalt, bismuth, and silver. Population about 4500. 



M'HKKC KHOKN. See A LI*, Vol. I. p. 576578. 



SCHLJMLA, or CIUMLA, a town of Turkey in Eu- 

 rope, and in the province of Silistria, on the road from 

 Constantinople to Wallachia. It has a castle and se- 

 veral handsome mosques. Hardware goods arc ma- 

 nufactured here, and ready made clothes from Con- 

 stantinople. The population is said to amount to 

 30,000. East long. 2(j 56', north lat. 43 25'. 



SCHWEITZ, the name of one of the Swiss cantons, 

 situated adjacent to the lakes of Zug and Lucerne. It 

 has a superficial extent of 46'0 square mile?. The prin- 

 cipal mountains are, Height in feet. 



Mytten, .... 6000 



Pregel, .... 5500 



liegi, - 6000 



The chief occupation of the inhabitants is the pas- 



turage of their cattle. The inhabitants who ire Ca- 

 tholic* amount to 30,000. " ' , ' 



Schweitz, the capital of the canton, is situated in a 

 valley about two miles from the lake of Lowerz. Tfe 

 houses a re good, and the chnrch is large. Population 50lHp 



>< mvi.l:l\, the capital of the grand duct. 

 Mecklenburg Schwerin, is pleasantly situated on the 

 Jake of Schwerin. The town, which is nearly square, 

 is divided into the old and the new, the moor and the 

 suburbs. The chateau or grand ducal palace, is situ- 

 ated on one of the charming islands of the lake. It in 

 fortified, and communicates by a draw. bridge with 

 the town. It contains a cabinet of natural history, a 

 gallery of pictures, and fine gardens. The duke has 

 also a fine chateau at Ludwigsburg, three miles from 

 Schwerin, which is built in the modern style, with an 

 English park. The principal public buildings ami 

 establishments in the city are the ci-devant cathedral 

 church, two Lutheran churches, a Catholic church, an 

 orphan's hospital, a poor's house, and a synagogue. 

 There are here several breweries and distilleries, and a 

 few trifling manufactures. 



Not far from Schwerin and Wismar, are the sea 

 baths of Dobberan, which are much frequented in July. 

 Near these baths are the holy dike, a bulwark of great 

 strength and antiquity, erected to keep off the sea. It 

 is built of large stones with cement, polished and or- 

 namented with figures analogous to those of the my- 

 thology of the northern nations. Population 8500. East 

 Long. 11 24', North Lat. 53' 40". 



SCIENCE, CURIOSITIES IN, 



Science, As it has been usual in works of this kind to collect 

 Curiosities under a general article what have been called Rational 

 in. Recreations, or popular experiments, founded on some 

 s - Y"*"^ scientific principle, or tending to illustrate some sci- 

 entific doctrine, we must, in obedience to the establish- 

 ed usage, present such a collection to our readers. 



We have made it our endeavour in all the scien- 

 tific treatises in this work, to have them drawn up in 

 as popular and intelligible a form as the subject would 

 admit, without compromising the scientific character 

 which all such articles must possess; and hence many 

 popular instruments and showy experiments have been 

 already fully described in this work. The subject, how- 

 ever, is far from being exhausted, and there still remains 

 a vast number of scientific wonders and curiosities of 

 which we have yet given no account. Many of them, 

 however, are of such a hackneyed character, having 

 appeared in so many works, and been so often the 

 theme of popular lectures and exhibitions, that we shall 

 direct the attention of our readers only to those which 

 seem the most interesting, or which are distinguished 

 by their brilliancy or their novelty, or by their im- 

 portance as leading facts in the history of science. 



Those who expect in this article a detail of tricks 

 and deceptions which belong to the province of leger- 

 demain, will be much disappointed. These have their 

 interest, like every thing else, but they have no claim 

 to a place in a Dictionary ofiise/ul knowledge. 



For the sake of method, we shall follow the alpha- 

 betical arrangement of the sciences. 



ACOUSTICS. 



1. Cn the Acoustic Figures produced by the Vibration 

 of Plates, 



Galileo long ago pointed out a method of showing the 



vibration of plates held horizontally, by covering the Science, 

 plate with fine sand, which accumulated in those parts Curiontie* 

 of the vibrating surface which were at rest. In the year * n ' 

 1787, M. Chladni of Wirtemberg made a great num. VS *Y"* >/ 

 ber of experiments on the nature of the vibrations pro- 

 duced by plates of glass of different shapes. In our 

 article ACOUSTICS, Vol. I. p. I-,>1, we have done little 

 more than mention these experiment?, and have given 

 a few specimens of the acoustic figures produced in 

 these experiments in Plate II. Fig. 5, 6, 7, 8, 9; but 

 as the subject is highly interesting, and as the experi- 

 ments may be easily repeated, we snail make no apology 

 for resuming the subject. 



The plates used in such experiments should be thin 

 plates of good window glass, from three to ten inches 

 in diameter, having their edges ground to the shape 

 required. The powder to be used may be very fine 

 sand, but Professor CKrsted, whom we have had the 

 pleasure of seeing repeat many of Chladin's experi- 

 ments, prefers the Lycopodium powder. 



In order to damp the vibrations of the plates in par- 

 ticular places, we have only to pinch them between 

 the finger and thumb of the left hand in the place 

 directed, and then set them a vibrating by drawing a 

 fiddle bow over their edge. Sometimes another place 

 may be damped by the application of another finger ot* 

 the left hand, or any points of the plates may be } 

 ed against one or more fixed objects. 



These methods of damping by the fingers, and by p 

 pressing against fixed obstacles, are shown in Plate c . 

 CCCCLXXXIII. Fig. 1, Fig. 1-3." 



In Fig. 1 . one part only is damped by being pinch, 

 ed between the fingers and thumb ; but it is easy to 

 damp another part by any of the three unoccupied 

 fingers of the same hand. 



In Fig. 2. the centre c of an elliptical plate is damp- 



